Real-time service orchestration is going to get much more complicated

There have always been flaws with the IMS service delivery model, particularly when customers subscribe to multiple services that may conflict with each other. With a new core network coming and an increased need to coordinate service capabilities across networks and real-time slices, it’s become more urgent than ever to resolve orchestration issues. This problem is part of an ongoing R&D activity performed by the Gintel team.

The IMS has long provided a platform for the deployment of multi-media services to subscribers across connected networks. It’s at the heart of most current networks and will likely continue to deliver for some time to come. Today, the new 5G standalone (5G-SA) architecture is eagerly anticipated. It’s expected to be the foundation of a whole new set of innovative services. But, for operators, new 5G-SA assets must sit beside existing service frameworks, such as the current IMS core.

Conceptually, this is straightforward – the IMS will simply appear as another IP network to the 5G-SA core – but in practice, it raises many challenges for service delivery and orchestration. It’s a topic we’ve been researching extensively, through collaboration with NTNU in Trondheim. This work has arisen because of well-known but long-standing issues with service delivery in the IMS.

Specifically, it has long been known that the orchestration of multiple services in parallel for specified users raised challenges. Processing services independently is one thing, but when multiple services have to interact, it can create conflicts.

The challenge of orchestration is easily illustrated with a simple example. If we have three subscribers in the same network, Alice, Bob and Charlie, and we consider two basic services, call forwarding (unconditional) and call barring, to which each subscribes.

Alice wants to block calls to and from Charlie, while Bob wants to forward all calls to Charlie. With the forwarding active, Alice calls Bob – which results in a forward to Charlie. While both services are active and correct, the outcome is undesirable from the perspective of Alice. Overcoming such conflicts is thus a key concern for the service provider.

Various efforts have been made to resolve these difficulties, which are inevitably compounded by scale (millions of subscribers, with proportionate triggering of services), such as the definition of the Service Capability Interaction Manager (or SCIM) by 3GPP. But, while defined as an entity, the specific functional requirements were not standardised, with the result that many interpretations have been realised by different vendors.

The recent research undertaken by the Gintel team has shown limitations with current approaches to resolving these conflicts – and suggested a new set of criteria for more effective service orchestration and management.

The need to solve this problem has become more pressing. Not only may subscribers use multiple services in parallel (as the example illustrates), they may seek to do so across different networks, so the context and capabilities available to them can change. What’s more, adding new 5G-SA to the mix will exacerbate the problem, as it’s likely to require yet more blended capabilities and create further conflicts – as well as complex changes brought about by the stateless architecture.

Worse, it will also require much greater volatility in terms of service activation, more diversity in terms of resources that can be called upon for a service, and, with the introduction of network slicing, a new level of dynamism. Coordinating services and resources across this environment will present significant challenges. A service solution may be called upon to provide capabilities for a wide range of services, across different network slices and with different quality and performance criteria.

So, we’re currently investigating new solutions to manage multiple services and to ensure that they can be orchestrated correctly, even as the complexity of the network and resources available changes. It’s the focus on ongoing and pioneering research, but it’s a key topic.

Put simply, deploying a new service is more than simply choosing a platform – it’s about integration with a complex real-time environment that is evolving and removing any possible conflict with other services. If you are considering how to orchestrate service chains and triggers in an increasingly complex heterogenous network, we can help. Get in touch for a discussion – and watch out for more insights into how we will address this challenge.

IMS, 5G, 5G-SA

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